Pertussis

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This is a highly contagious bacterial respiratory tract infection common in children and adults. The incubation period is 7-21 days. 

Complications  include  subconjunctival haemorrhage, otitis media, apnoea, pneumonia, bronchiectasis, activation of latent tuberculosis, dehydration, fever, convulsions, rectal prolapse, and malnutrition. Admit to hospital when complications are present. 

Pertussis can be prevented by the “five-in-one”  immunisation recommended for all children (See section on ‘Immunisation’).

In the event of a child developing pertussis before immunisation, the  “five in one” vaccine should still be given to protect against the four other diseases.

During epidemics, or when there is a clear history of contact in a child with catarrh, appropriate antibiotics may help reduce the period of  infectivity and transmission. All cases should be reported to the District Disease Control Officer.

Cause

  • Bordetella pertussis

Symptoms

Catarrhal Phase: Initial 1-2 weeks 

  • Low grade fever
  • Nasal discharge
  • Mild cough

Paroxysmal phase: within the following 6-10 weeks 

  • Episodes of violent repetitive cough ending with inspiratory whoop or vomiting (whoop may be absent in babies and adults)

Recovery (convalescent) phase: next 2-3 weeks

  • Gradual reduction in bouts of coughing

Signs

  • Apnoea (long pause in breathing) common in babies
  • Cyanosis

Investigations

  • FBC - high total lymphocyte count
  • Chest X-ray (to exclude other causes of chronic cough)

TreatmentTreatment Objectives

  • To reduce transmission
  • To prevent complications

Non-pharmacological treatment

  • Feed frequently between coughing spasms
  • Encourage adequate oral fluid intake

Pharmacological treatment

Patients and close contacts within 14 days of onset of symptoms

1st Line Treatment

Evidence Rating: [A]

  • Erythromycin, oral, 

Adults

500 mg 6 hourly for 7 days

Children 

8-12 years; 250-500 mg 6 hourly for 7 days

2-8 years; 250 mg of suspension 6 hourly for 7 days 

6 months-2 years; 125 mg of suspension 6 hourly for 7 days

< 6 months; not recommended (risk of pyloric stenosis) - consider Trimethoprim/Sulphamethoxazole instead. (See below).

OR

Evidence Rating: [B]

  • Azithromycin, oral,

Adults

500 mg daily for 3 days

Children

10 mg/kg body weight daily for 3 days

(not recommended for children less than 6 months because of a risk  of pyloric stenosis) - consider Trimethoprim/Sulphamethoxazole instead. (See below).

OR

Evidence Rating: [C]

  • Clarithromycin, oral,

Adults

500 mg 12 hourly for 7 days 

Children

7.5 mg/kg 12 hourly for 7 days

2nd Line Treatment

Evidence Rating [C]

  • Trimethoprim/Sulphamethoxazole, oral,

Adults

160/800 mg 12 hourly for 7 days  

Children

4/20 mg/kg 12 hourly for 7 days

Oxygen therapy when oxygen saturation <92%

Oxygen, intranasal or face mask, (if the patient has difficulty in breathing or is cyanosed)

Referral Criteria

  • Refer infants who have an episode of apnoea or cyanosis after initial resuscitation to a specialist.